A reprieve for Moore’s law?

In 1965, Gordon Moore, one of the co-founders of Intel, observed that the number of transistors on a computer chip doubles about every 18 months, leading to regular increases in processing speed and power.

This observation, known as Moore’s law, has held sway for the last 35 years, but many Scientists now believe that the limits of physics will soon make it impossible for computer development to continue at this pace. Indeed, some observers have predicted that Moore’s Law will hit a brick wall in about a decade.

Researchers are concerned that, as transistors are shrunk below 100 nanometers, it will be difficult to maintain high performance and fabrication quality.

The major problem is that conventional silicon transistors, the on-off switches that make solid-state electronics possible, will cease to function below a certain thickness. That’s because at such thin dimensions quantum mechanics — in which electrons behave as both waves and particles — begin to have a measurable effect on performance. Essentially, the ultra-thin layer of insulating material in such small transistors will fail to stop electrons from flowing, and the transistor will no longer function as a switch.

However, research carried out by engineers at Purdue University in the US indicates that this bleak outlook may be a little premature.

A new simulation tool has shown that an innovative type of transistor could keep the pace of computer development at its current level until 2025, giving scientists breathing room to develop technologies to replace integrated circuits made from silicon.

The simulation tool, developed by Mark Lundstrom and Supriyo Datta, professors of electrical and computer engineering at Purdue, tested the performance of an experimental transistor, called a double-gate transistor, which carries twice the electrical current and works more than twice as fast as conventional devices.

Lundstrom has demonstrated that double-gate transistors one-tenth the length of the best conventional transistors could perform as well as current devices. Critical components in the transistors, electrodes known as gates, are only 10 nanometers long, compared to 100 nanometers for conventional transistors. The new simulation tool evaluates transistor performance with a sophisticated technique earlier used to simulate electrical conduction in individual molecules. When applied to transistors, the same method predicts that a double-gate transistor can continue to perform well at gate lengths as short as 10 nanometers, and perhaps even shorter.

Researchers at Purdue, the University of California at Berkeley and the IBM Watson Research Center have already demonstrated working double-gate transistors.

The simulation tool, called nanoMOS, is now available to any researcher who wants to use it through the Purdue Nanotechnology Simulation Hub, or nanoHub, a network-computing platform that automatically enables computer users to run programs with conventional Web browsers. They simply acquire an account and begin using the software.

Purdue researchers say they know of only two other teams in the world who have created similar ‘full quantum’ simulation tools. But those tools were developed in the private sector and are not accessible to the research community at large.